Energy Star: Joint effort by the U.S. Environmental Protection Agency, or EPA, and the U.S. Department of Energy, or DOE, to help consumers save money and protect the environment through energy-efficient products and practices. The term also represents a government certification that an appliance meets federally-set guidelines for energy use. Seen by many as the "gold standard" when it comes to rating energy use of home products.

Ethanol:
Also known as grain alcohol, or ethyl alcohol,
it's a colorless liquid produced by fermentation
used in alcoholic beverages, industrial processes
and as a fuel additive.

Fluorescent light: A device that produces visible light by passing an electric charge through gaseous atoms in a glass tube. These atoms emit ultraviolet radiation that is absorbed by a phosphor coating on the walls of the lamp tube. The phosphor coating produces visible light.

Fossil fuels:
Fuels formed in the ground from the remains
of dead plants and animals. It takes millions
of years to form fossil fuels. Oil, natural
gas and coal are fossil fuels.

Fuel oil: Any liquid petroleum product burned to generate heat in a furnace or firebox, or to generate power in an engine.

Gasohol: A registered trademark of an agency of the state of Nebraska, for an automotive fuel containing a blend of 10 percent ethanol and 90 percent gasoline.

Gasoline: A refined petroleum product suitable for use as a fuel in internal combustion engines.

Generator: A device for converting mechanical energy to electrical energy.

Geothermal energy: Energy produced by the internal heat of the earth. Geothermal energy can be used directly for heating or to produce electric power.

Geothermal heat
pump: A type of heat pump that uses
the ground, ground water or ponds as a heat
source and heat sink, rather than outside
air. Ground or water temperatures are more
constant and are warmer in winter and cooler
in summer than air temperatures. Geothermal
heat pumps operate more efficiently than "conventional"
or "air source" heat pumps.

Gigawatt
(GW): A unit of power equal to 1 billion
watts, 1 million kilowatts or 1,000 megawatts.

Global warming: A common term used to describe the increase in average global temperatures due to the greenhouse effect.

Grain alcohol: Ethanol.

Global climate change (GCC): Global climate change is a significant switch from one climatic condition to another -- not including normal fluctuations in various climates around the world -- as the result of human activities. The greatest of these is fossil fuel combustion, which traps greenhouse gases in the atmosphere, causing gradual changes in Earth’s temperatures over hundreds of years.

Advertising Disclosure: Bankrate.com is an independent, advertising-supported comparison service. Bankrate may be compensated in exchange for featured placement of certain sponsored products and services, or your clicking on links posted on this website.